This application claims benefit of Japanese Application No. 2000-189919 filed in Japan on Jun. 23, 2000, the contents of which are incorporated by this reference.
1. Field of the Invention
The present invention relates to an endoscope, and more particularly to an endoscope having a soft flexible tube in the insertion part wherein at least one elongated integrated object is disposed in the flexible tube.
2. Description of the Related Art
An endoscope for medicine which is inserted into the body for observing internal organs by inserting the elongated insertion part, or allows various treatments using a treatment instrument inserted into the treatment instrument channel if required is widely used.
Particularly an endoscope used in the medical field is used for observing internal organs by inserting the insertion part into the body or allows medical treatment using a treatment instrument inserted in the treatment instrument channel of the endoscope. Therefore cleaning and disinfecting the endoscope device must be performed after inspection and treatment end when an endoscope and treatment instruments used once are used again for another patient, so that infection between patients via the endoscope and instruments is prevented.
Recently autoclave sterilization, which does not involve a complicated operation, and which allows using the equipment immediately after sterilization with low running cost, is becoming the standard sterilization processing of a medical instrument.
Japanese Unexamined patent publication No. H10-276968 discloses an endoscope wherein a fluororesin tube is used for the flexible tube enclosed to pass fluid or treatment instruments, and annealing is performed before incorporating the fluororesin tube into the endoscope, so that the internal tube does not shrink when sterilization is performed by autoclaving, and sufficient sterilization processing can be performed repeatedly.
However, in the case of the endoscope in Japanese Unexamined patent publication No. H10-276968, annealing processing on the fluororesin tube is performed before incorporating the tube into the endoscope, so if the endoscope is autoclaved, for example, the flexible tube constituting the insertion part which is not annealed may shrink in the longitudinal direction by thermal load during autoclaving.
In other words, the entire flexible tube shrinks, and the annealed fluororesin tube inside the flexible tube hardly shrinks. Therefore the fluororesin tube becomes loose compared with the flexible tube, and the tube itself may be easily buckled.
Also other objects integrated inside the flexible tube, such as a light guide for supplying illuminating light (hereinafter xe2x80x9clight guidexe2x80x9d) and a signal transmission cable for transmitting electric signals from an image pick-up means, are pressed by a loosened tube, and the movement of these objects is obstructed or such problems as the buckling of integrated objects and cable disconnection occur.
Also, when annealing the fluororesin tube incorporated into the endoscope, normally several loops of long fluororesin tube are placed in a furnace for annealing. This curls the fluororesin tube, which makes it difficult to incorporate the tube into the endoscope. If a curled fluororesin tube is incorporated into the endoscope, this fluororesin tube obstructs the movement of the integrated objects, such as a light guide and signal transmission cable, which are pressed by the fluororesin tube, and such problems as buckling and disconnection may occur, also the curl of the tube may negatively affect the insertion of the endoscope itself.
Incorporating an unannealed fluororesin tube into the endoscope has been widely performed. However, if this endoscope is autoclaved, the unannealed fluororesin tube shrinks in the longitudinal direction. Then the fluororesin tube is pulled from both ends of the flexible tube, load is applied to the connection parts at both ends of the fluororesin tube, and problems may occur.
With the foregoing in view, it is an object of the present invention to provide an endoscope where problems due to an increase in the difference of the deformation amount in the longitudinal direction between the flexible tube and an integrated object during autoclaving are prevented.
An endoscope according to the present invention is an endoscope which comprises a flexible insertion part having an elongated flexible tube, and at least one elongated integrated object which is directly or indirectly secured to both ends of said flexible tube, wherein there is disposed deformation control means for controlling an increase of the absolute value of the difference between the deformation amounts in the longitudinal direction of said flexible tube and said at least one elongated integrated object with respect to a predetermined thermal load.
Also, according to the present invention, the endoscope which comprises an insert part having an elongated flexible tube, and at least one elongated integrated object which is directly or indirectly secured to both ends of said flexible tube, wherein the shrinkage factors of said flexible tube and said integrated object in the longitudinal direction with respect to a predetermined thermal load are roughly the same.
Further, according to the present invention, the endoscope comprising an insertion part having an elongated flexible tube, and at least one elongated integrated object which is directly or indirectly secured to both ends of said flexible tube, wherein the deformation amount in the longitudinal direction and deforming directions of said flexible tube and said integrated object with respect to a predetermined thermal load are roughly the same.
The above and other objects, features and advantages of the invention will become more apparent from the following description when taken in conjunction with the accompanying drawings.